There are three kinds of teaching by the Catholic Church:
Among which, divinely revealed truths and teachings on faith and morals are infallible.
The doctrine of infallibility does not stop at the pope, but also extends to the ecumenical councils and the bishops. However, bishops cannot declare doctrines on their own, rather, only when they are in union with the Catholic Church that their words can be taken to be infallible.
This is clearly defined in the Congregation for the Doctrine of the Faith, canon 750
§ 1. Those things are to be believed by divine and catholic faith which are contained in the word of God as it has been written or handed down by tradition, that is, in the single deposit of faith entrusted to the Church, and which are at the same time proposed as divinely revealed either by the solemn Magisterium of the Church, or by its ordinary and universal Magisterium, which in fact is manifested by the common adherence of Christâs faithful under the guidance of the sacred Magisterium. All are therefore bound to avoid any contrary doctrines.
§ 2. Furthermore, each and everything set forth definitively by the Magisterium of the Church regarding teaching on faith and morals must be firmly accepted and held; namely, those things required for the holy keeping and faithful exposition of the deposit of faith; therefore, anyone who rejects propositions which are to be held definitively sets himself against the teaching of the Catholic Church.
One question that one might have is,
Wasn't the teaching of infallibility only defined in 1870, which has no apostolic backing?
At first, this seems like the teaching of infallibility has no basis, and is a circular argument. However, 1870 is when only the term of infallible teaching was defined - ex cathedra. The teachings of the Church has been being held infallible since the start of Church, not only since ex cathedra was defined. It is only when the papal infallibility was called into question that the doctrine was defined.
From the definition of papal infallibility, we can see that the pope is not infallible in many aspects. In fact, errors made by the pope in other areas does not compromise his infallibility in teachings of divinely revealed truths and faith and morals.
Popes are by no means perfect in their personal lives. We see that even Peter was not perfect in his life, while his teachings can still be held infallible.
Formosus was a bishop in Porto-Santa Rufina (a region in Italy), and was sent as a legate in Bulgaria. He was so successful that Bulgarian ruler Boris I asked the then-pope to appoint Formosus as the bishop of Bulgaria. The request was not accepted as that would violate fifteenth canon of the Second Council of Nicaea.
Afterwards, the new pope John VIII excommunicated with Formosus, accusing him of corrupting the minds of Bulgarians that they would not accept any other bishop. According to rumours, Formosus begged for forgiveness, in exchange he would forgo his bishop office and live as a layman. Formosus then became the next pope.
Formosus supported (Carolingian) Arnulf, who invaded Rome. Formosus crowned him to oppose Lambert. Lambert re-entered Rome afterwards, and forced the next pope Stephen VI to conduct the trial of ex-pope Formosus.
In the Cadaver synod, Stephen VI exhumed and tried Pope Formosus' corpse, his predecessor. Stephen VI accused him of perjury, and the corpse of pope Formosus could not respond to his questioning. Pope Stephen VI then displayed his corpse through Rome and finally dumped the corpse in Tiber River. [ref]
He led a "depraved" and "worldly" life, where his Lateran Palace was described as a brothel.
He was also a prince of Rome. His enemies used this to blacken his reputation.
In Synod of Rome 963, John XII was accused of sacrilege, simony, perjury, murder, adultery, and incest, and was summoned in writing to defend himself. [ref]
According to rumours, John died during an act of adultery.
He also made an oath with Otto I that he will only support him, not Adalbert. Out of fear for Otto I, John conspired against him and supported Adalbert.
Pope Benedict IX was the only pope known for selling the papacy. Benedict offered his godfather, John Gratian, if John would reimburse Benedict with his election expenses. The deal went through, and John was eventually elected as pope, Gregory VI.
He then even attempted to reclaim the papal office twice. [ref]
Alexander VI was father of several children by his mistresses. Some were even officially recognised: Juan, Cesare, Jofré, and Lucrezia [ref]
He also engaged in nepotism:
Popes are only guaranteed to be infallible in their teachings not their life. In fact, Peter denied Jesus 3 times when Jesus was tried. Though Peter believed in the salvation for the Gentiles, he did not fully practice what he said, as we will see in Paul's confrontation with Peter. More details are included in the section on Peter. Such Peter's actions do not undermine his authority to teach definitively, and similar to the current pope and the magisterium.
Pope's teachings are considered infallible only when he invokes the power of the Church, not in his personal letters or personal words. There are many incidents where the pope talked of the wrong teaching. However, in such cases, the pope never invoked the authority of the chair of Peter.
Pope Honorius I was condemned for not condemning monothelitism, which says that Jesus only has one will (one nature) - i.e. only divine will, not human will. [ref]
Sergius was the Patriarch (Bishop) of Constantinople. Sergius wrote a letter to pope Honorius I, asking for his opinion on monothelitism. In his letter to Sergius, pope Honorius replied:
Pope Honorius' reply was not a declaration of faith or dogma, and did not claim to speak with the papal authority.
Sergius went further to tell people to confess one will in Jesus, and avoid the terms, declaring it "truly agreeing with the Apostolic preaching." By which time, Honorius was already dead.
Pope St Agatho then later used the authority as successor of Peter, and the Third council of Constantinople, to condemn monothelitism, and declared two natures. In the same letter, pope Honorius I was anathematized (excommunicated). [ref]
Bishops in Africa condemned Pelagius for his heresies, so he sent his profession of faith, first time by a servant, second time in a letter, to pope Zozimus. Pope Zozimus did not find anything wrong with the profession, and so instructed those bishops in Africa against Pelagius to appear in Rome for further investigation.
However, in reality, Pelagius,
What Pelagius exactly included in his exchange with pope Zozimus could not be verified.
Pope Zozimus' actions outraged the bishops in Africa, as they considered the controversy to have been closed by the previous pope Innocent I. Zozimus then backed down, explaining that he had not settled the matter definitively, and wished to consult the African bishops further on the matter. The bishops provided Zozimus with additional evidence against Pelagius, after which the pope condemned Pelagius.
In both of the cases above, we see that the pope only made errors in his personal actions or letters. However, the pope, and the magisterium in general, did not make doctrinal errors when speaking with the authority of the Church. Pope's personal opinions in no way undermine the authority of the papal office.
The church is not responsible for teaching science. And contrary to popular belief, the Catholic Church as a whole does not assert any scientific statement.
The church previously approved of the idea of geocentrism, i.e. the Earth is the center of the universe, and the Sun rotates around the Earth. This in part is due to the literal interpretation of the Bible. In fact, many verses in the Bible, if taken literally, suggests that the Earth should be the center of rotation, and should not move around another object.
Joshua 10:13
"Sun, stand thou still at Gibeon,
and thou Moon in the valley of Ai'jalon."
And the sun stood still, and the moon stayed,
until the nation took vengeance on their enemies.
Is this not written in the Book of Jashar? The sun stayed in the midst of heaven, and did not hasten to go down for about a whole day.
Psalms 93:2
Yea, the world is established; it shall never be moved;
thy throne is established from of old;
thou art from everlasting.
Psalms 104:5
Thou didst set the earth on its foundations,
so that it should never be shaken.
Ecclesiastes 1:5
The sun rises and the sun goes down,
and hastens to the place where it rises.
However, the more compelling reason was because, the church simply reiterates what Ptolemy and Aristotle had asserted in the past. The Catholic Church never asserted that only geocentrism was correct.
Copernicus first proposed the idea of heliocentrism, i.e. the Sun is the centre of the universe, and the Earth rotated around the Sun. It was then verified by Galileo's experiments with his new telescope.
For the record, Martin Luther was even more against the theory than the Catholic Church, which was the reason why Galileo shared his findings with the Catholic Church rather than the Protestant church. [ref] . "However, as Holy Scripture tells us, so did Joshua bid the sun to stand still and not the earth." [ref]
Cardinal Robert Bellarmine, a Jesuit, fearing the opposition from traditional scientists, who believed in geocentrism, forbade Galileo from defending heliocentrism, but did not forbid him from conjecturing it. [ref]
Pope Urban VIII was interested in Galileo's theory. He gave his viewpoint to Galileo, that God could do anything, regardless of the laws of Physics. Galileo then quoted the pope on this to criticise the pope, saying that the pope used the Lord as explanation to everything because of his ignorance. The pope then ordered the arrest of Galileo. [ref]
Have you heard of the following ideas: in the Medieval time, many seafarers did not make it back, because, the Catholic Church asserted, that they fell off the edges of the Earth?
Perhaps you have not. But I have heard this many times when I studied history in Vietnam.
However, this is a total myth. For a very long time, the Catholic Church actually held onto the belief that the Earth is spherical. [ref] [ref] In fact, many scientists in the past have held on to the belief that the Earth was round, not just the Catholic Church. It was only in the 19th century that the Fundamentalist movement raise the idea of the flat Earth, claiming that it is suggested in the Bible, with the phrase "four corners of the earth."
The myth also came from many writings that exaggerated Medieval ignorance of the round Earth, to highlight the conflict between science and religion, particularly writings by Christopher Columbus, A History of the Life and Voyages of Christopher Columbus, and John William Draper, History of the Conflict between Religion and Science. But this myth is in no way true.
We see that the Catholic Church never actually made an infallible teachings on the topics of science. The Catholic Church was never in a position to declare which scientific statements should be correct and which should not.
In the case of geocentrism vs heliocentrism, the Catholic Church was involved in the controversy only because it could face the truth better than the Protestant church. In the case of flat Earth theory, it was a total myth, as the Catholic Church never subscribed to the idea.
Jesus has given the apostles the authority to teach infallibly.
Matthew 18:17-18
If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector. Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.
That is, whatever the apostles declare on Earth, God will ratify in heaven. It is not that God is bound by whatever the apostles say, but it is that the apostles are free from error in their teachings about God.
Similarly, in the last supper, Jesus has restated their gift of teaching infallibly,
Luke 22:28-30
You are those who have continued with me in my trials; as my Father appointed a kingdom for me, so do I appoint for you that you may eat and drink at my table in my kingdom, and sit on thrones judging the twelve tribes of Israel.
At the very beginning of the Catholic Church, the power to teach authoritatively does not stop at the head of the church, but also applies to the apostles.
Jesus has promised to them the gift of the Holy Spirit, which protected them against doctrinal errors, and revealed to them all they need to know to preach the Gospel.
John 14, 16-17, 26
And I will pray the Father, and he will give you another Counselor, to be with you for ever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him; you know him, for he dwells with you, and will be in you. ... But the Counselor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your remembrance all that I have said to you.
John 16:12-13
I have yet many things to say to you, but you cannot bear them now. When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come.
As successors of the apostles, teachings declared by the pope and the bishops (the magisterium) are inspired by the Holy Spirit, not themselves.
So then, what is so special about Peter, if he is just one of the apostles who can teach infallibly? Well, the pope is the foundation of the Catholic Church, the sign of unity of the Church. Peter himself was the first pope.
Jesus has singled out Peter, and declared him the foundation of the Church.
Matthew 16:18-19
And I tell you, you are Peter, and on this rock I will build my church, and the powers of death shall not prevail against it. I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.
Notice that Peter was similarly given the power to teach authoritatively, which was also given to the apostles later on. However, we have to notice, the key difference here is that, Peter was declared to be the "rock" and hold the "keys of the kingdom of heaven."
This is in direct reference to Isaiah 22:21-22,
I will clothe him with your robe, and will bind your girdle on him, and will commit your authority to his hand; and he shall be a father to the inhabitants of Jerusalem and to the house of Judah. And I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open.
This power is special, in reality, it is to decide whether a council is ecumenical. Peter holds a special position to ensure that the Catholic Church does not sway away from the truth. In fact, Jesus once again singled out Peter in the upper room during the last supper,
Luke 22:31-32
Simon, Simon, behold, Satan demanded to have you, that he might sift you like wheat, but I have prayed for you that your faith may not fail; and when you have turned again, strengthen your brethren.
Sifting like wheat suggesting that Peter will go through trials, and under the hands of Satan, Peter would be helpless. But his faith would never fail, suggesting that his teachings on faith topics will be free from error. And Peter is the one to "strengthen your brethren", suggesting that Peter holds the ultimate authority to determine what is right and what is wrong, regarding the matter of church teachings.
In fact, Peter was given the authority as the leader of the church even when he was not perfect. Even when Peter expressed so to Jesus. We see that when Jesus appeared to the apostles, Jesus again singled out Peter and instructed him to "feed my lambs,"
John 21:15-17
When they had finished breakfast, Jesus said to Simon Peter, "Simon, son of John, do you love me more than these?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Feed my lambs." A second time he said to him, "Simon, son of John, do you love me?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Tend my sheep." He said to him the third time, "Simon, son of John, do you love me?" Peter was grieved because he said to him the third time, "Do you love me?" And he said to him, "Lord, you know everything; you know that I love you." Jesus said to him, "Feed my sheep."
Notice that in Greek, the "love" words in bold are agape, meaning unconditional, selfless love, while the "love" words with underline are phileo, meaning the love of friendship. Jesus wanted Peter to love him uncondtionally, selflessly. But Peter was not ready, and instead answered with a love of friendship.
And that was alright, Jesus ultimately accepted the phileo love that Peter at that time offered. But Jesus hinted Peter that, ultimately, Peter would achieve agape love for Jesus.
John 21:18
Truly, truly, I say to you, when you were young, you girded yourself and walked where you would; but when you are old, you will stretch out your hands, and another will gird you and carry you where you do not wish to go.
This was hinting at the fact that Peter would die in the name of Jesus, which was an ultimate sign of agape love.
Peter believed in and preached about the salvation for the Gentiles, but he did not always practice as he preached. In fact, later into his apostolic life, he separated himself from the Gentiles, which was recounted in Paul's confrontation with Peter:
Paul's confrontation with Peter
Galatians 2:11-14
But when Cephas came to Antioch I opposed him to his face, because he stood condemned. For before certain men came from James, he ate with the Gentiles; but when they came he drew back and separated himself, fearing the circumcision party. And with him the rest of the Jews acted insincerely, so that even Barnabas was carried away by their insincerity. But when I saw that they were not straightforward about the truth of the gospel, I said to Cephas before them all, "If you, though a Jew, live like a Gentile and not like a Jew, how can you compel the Gentiles to live like Jews?"
However, his actions in no way undermine his infallible teaching of salvation for the Gentiles.
Popes are not necessarily the most virtuous people, who lead perfect lives. As we see in the case of Peter, God accepted an imperfect person to lead his flock.
A question that comes to our mind that, did Peter ever exercise his authority as pope? Or was the authority of the pope only invented later on?
In the book of the Acts, Peter was the first to declare the doctrine of salvation for the Gentiles. He was the first to be revealed to, by God, that the Gentiles should be received into the house of God too.
Acts 10:11-15
[Peter] saw the heaven opened, and something descending, like a great sheet, let down by four corners upon the earth. In it were all kinds of animals and reptiles and birds of the air. And there came a voice to him, "Rise, Peter; kill and eat." But Peter said, "No, Lord; for I have never eaten anything that is common or unclean." And the voice came to him again a second time, "What God has cleansed, you must not call common."
This goes to show that, the Gentiles, by God's grace, can be cleansed too, and should not be excluded from the Church. And God sent an angel to Cornelius, a Gentile centurion, to tell him to invite Peter to his house. Cornelius was a God-fearing man who gave alms liberally and prayed constantly to God.
Acts 10:3-5
About the ninth hour of the day he saw clearly in a vision an angel of God coming in and saying to him, "Cornelius." And he stared at him in terror, and said, "What is it, Lord?" And he said to him, "Your prayers and your alms have ascended as a memorial before God. And now send men to Joppa, and bring one Simon who is called Peter
Initially, Peter could not understand the vision in his dream. But when the servants and soldier sent by Cornelius to Peter, and Peter was invited to Cornelius' place, getting the opportunity to preach the Gospel, Peter finally understood the vision. Even though the Gentiles are not circumcised, which was necessary at the time according to the Jewish traditions, Peter preached the Good News to them and ordered them to be baptised in the name of Jesus. It was also at that time that the Gentiles also received the gift of speaking tongues and extolling God.
Acts 10:45-48
And the believers from among the circumcised who came with Peter were amazed, because the gift of the Holy Spirit had been poured out even on the Gentiles. For they heard them speaking in tongues and extolling God. Then Peter declared, "Can any one forbid water for baptizing these people who have received the Holy Spirit just as we have?" And he commanded them to be baptized in the name of Jesus Christ. Then they asked him to remain for some days.
I recommend you to read Acts 10 in details to get the rest of the details.
In fact, this was not something agreed upon among the apostles previously. And Peter used his authority to assert that the Gentiles could be saved too, explaining it to the other apostles.
Acts 11:2-4,15-18
So when Peter went up to Jerusalem, the circumcision party criticized him, saying, "Why did you go to uncircumcised men and eat with them?" But Peter began and explained to them in order: ... As I began to speak, the Holy Spirit fell on them just as on us at the beginning. And I remembered the word of the Lord, how he said, 'John baptized with water, but you shall be baptized with the Holy Spirit.' If then God gave the same gift to them as he gave to us when we believed in the Lord Jesus Christ, who was I that I could withstand God?" When they heard this they were silenced. And they glorified God, saying, "Then to the Gentiles also God has granted repentance unto life."
Peter was the one to declare the doctrine that the Gentiles could be saved! And in fact, the Gentiles, too, received the gift of the Holy Spirit to speak of God.
Later on, in the book of Acts, another discussion popped up among the apostles, as for whether the Gentiles need to be circumcised. This was at the council of Jerusalem, where the apostles gathered to discuss the matter.
Acts 15:1,5
But some men came down from Judea and were teaching the brethren, "Unless you are circumcised according to the custom of Moses, you cannot be saved." ... But some believers who belonged to the party of the Pharisees rose up, and said, "It is necessary to circumcise them, and to charge them to keep the law of Moses."
Many believed that one must be circumcised to be saved. Peter was the first one to stand up to assert that the Gentiles do not need to be circumcised in order to be saved.
Acts 15:7-11
And after there had been much debate, Peter rose and said to them, "Brethren, you know that in the early days God made choice among you, that by my mouth the Gentiles should hear the word of the gospel and believe. And God who knows the heart bore witness to them, giving them the Holy Spirit just as he did to us; and he made no distinction between us and them, but cleansed their hearts by faith. Now therefore why do you make trial of God by putting a yoke upon the neck of the disciples which neither our fathers nor we have been able to bear? But we believe that we shall be saved through the grace of the Lord Jesus, just as they will."
The grace of God is the one saving the Gentiles, not circumcision. Some other apostles, Paul, Barnabas, James, then ratified Peter's view. The council eventually sent a letter to the Gentiles to assure them that they have no greater burden than keeping their works, implying that circumcision was not necessary. I would recommend you to read Acts 15 in full to get better details of the council of Jerusalem.
In short, Peter had many times exercised his authority as the pope. He did not strictly contradict with the apostles' belief, in fact, that is not what the pope does most of the times, but rather, he swayed the Church into the correct direction.
Many early church fathers acknowledged the special role and power that Peter held.
Prescription against Heretics, chapter 22
Was anything withheld from the knowledge of Peter, who is called the rock on which the church should be built, who also obtained the keys of the kingdom of heaven, with the power of loosing and binding in heaven and on earth?
The author acknowledged that because Peter was the "rock" and the holder of the "keys of the kingdom of heaven," that he had the true knowledge of God, so that he could preach infallibly about God.
Tertullian, on Modesty, chapter 21
If, because the Lord has said to Peter, Upon this rock will I build My Church, to you have I given the keys of the heavenly kingdom; or, Whatsoever you shall have bound or loosed in earth, shall be bound or loosed in the heavens, you therefore presume that the power of binding and loosing has derived to you, that is, to every Church akin to Peter, what sort of man are you, subverting and wholly changing the manifest intention of the Lord, conferring (as that intention did) this (gift) personally upon Peter?
It is going against the bible when one denies the authority that Peter held, because Jesus himself conferred this gift personally upon Peter, not one time, but multiple times.
Epistle of Clement to James, Chapter I
Be it known to you, my lord, that Simon, who, for the sake of the true faith, and the most sure foundation of his doctrine, was set apart to be the foundation of the Church, and for this end was by Jesus Himself, with His truthful mouth, named Peter, the first-fruits of our Lord, the first of the apostles
There are more that I can quote. In the 200s - 300s, there were many giving testimony to Peter's power. I encourage you to read more here.
Peter called himself a fellow elder,
1 Pet 5:1
So I exhort the elders among you, as a fellow elder and a witness of the sufferings of Christ as well as a partaker in the glory that is to be revealed.
We have to read this in context to understand what he means. This is not Peter saying that he is not the leader of the church, but rather, he was teaching humility. Reading on,
1 Pet 5:5-6
Likewise you that are younger be subject to the elders. Clothe yourselves, all of you, with humility toward one another, for "God opposes the proud, but gives grace to the humble." Humble yourselves therefore under the mighty hand of God, that in due time he may exalt you. Cast all your anxieties on him, for he cares about you.
Likewise, Paul has many times called himself a servant. For example,
1 Cor 3:5
What then is Apol'los? What is Paul? Servants through whom you believed, as the Lord assigned to each.
It does not mean that Paul is just a servant, but rather, he was saying that church elders are servants of the people, assigned by the Lord.
1 Tim 3:15
I hope to come to you soon, but I am writing these instructions to you so that, if I am delayed, you may know how one ought to behave in the household of God, which is the church of the living God, the pillar and bulwark of the truth.
This verse states that the Church is the household of God, the pillar and bulwark of truth, emphasising the Church's role as the foundation and support for the truth.
1 Timothy 3 also shows deacons and bishops (by specifying their qualifications) as part of the structure of the church.
Luke 10:16
He who hears you hears me, and he who rejects you rejects me, and he who rejects me rejects him who sent me.
Jesus commanded the apostles to teach. Here, he reaffirms that he works through the apostles to advance the kingdom of God, and that if someone rejects those to whom he gives authority, they reject him and the Father who sent him.
2 Tim 2:1-2
You then, my son, be strong in the grace that is in Christ Jesus, and what you have heard from me before many witnesses entrust to faithful men who will be able to teach others also.
St Paul himself appointed bishops (faithful men) as his successors. One such example is St Timothy, as seen from his letter to Timothy above.
Titus 1:5
This is why I left you in Crete, that you might amend what was defective, and appoint elders in every town as I directed you.
Similarly, Paul wrote to Titus to appoint bishops (previously called elders), as seen from the verse above.
Letter to the Smyrnaeans by St Ignatius of Antioch (110 AD)
It is well to reverence both God and the bishop. He who honours the bishop has been honoured by God; he who does anything without the knowledge of the bishop, does [in reality] serve the devil.
This shows that we should follow the bishops and honour the bishops. Let's take a look at the passage below:
Letter of St Irenaeus, Against Heresies, Chapter 3 (180 AD)
[we do this, I say,] by indicating that tradition derived from the apostles, of the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul; as also [by pointing out] the faith preached to men, which comes down to our time by means of the successions of the bishops. For it is a matter of necessity that every Church should agree with this Church, on account of its preeminent authority.
This letter shows that the Roman Catholic church has the greatest authority, and there should be succession of bishops who help preach faith to men.
The authority of the councils naturally follows the authority of the magisterium. Here I would like to present some counter-arguments against the validity of the councils.
But didn't the pope attend any ecumenical council in the first millenial?
Yes, the pope did not attend any ecumenical council in the first millenial. However, the pope still has to approve of the works of the council in order for it to be declared ecumenical. In each council, the decree could be made by the council as a whole, and does not need to be made specifically by the pope.
There are instances where the council is not declared ecumenical because of the pope's final say. In the second council of Ephesus, all bishops agreed on a heresy, but only the pope rejected the decision. The council was therefore declared not ecumenical.
The council involved violence, with many opponents of Monophysitism being excommunicated from the council. (St) Pope Leo absolved all those condemned, and excommunicated all those who took part in the council.
There was a period where there were 3 rival claimants to papacy. Due to political reasons, popes had come to reside in Avignon, but pope Gregory XI returned the papacy to Rome. He died in 1378.
A conclave in Rome elected Urban VI in 1378, taking residence in Rome. Later that year, Urban VI fell out of favour and hence a new conclave was held, electing Clement VII, taking residence in Avignon, France. Both died before the rivalry was resolved.
The council of Constance finally settled the matter in 1414.
Notice that only successors in Rome were recognised as popes. During this time, even when there were rival claimants of the pope, but the line of (recognised) popes is preserved. [ref]
Martin V formally closed the council.
The council ultimately had to be approved by a pope. Even though there were rival claimants, that does not mean the papal office was compromised. Rival claimants, which are a result of human actions, do not reduce the legitimacy of the authority of the pope.
Heb 13:7
Remember your leaders, those who spoke to you the word of God; consider the outcome of their life, and imitate their faith.
Heb 13:17
Obey your leaders and submit to them; for they are keeping watch over your souls, as men who will have to give account. Let them do this joyfully, and not sadly, for that would be of no advantage to you.
In the letters to Hebrew, the author stresses that we should remember, obey and submit to the leaders who spoke to us the word of God. These instructions become meaningless if each of us has the authority to choose our own personal âleadership.â We can easily undermine the need for obedience to Church leadership by declaring ourselves leaders to some other leadership of our own choosing.
This shows Church leadership as part of the structure of the Church.
What was the Early Church's View on this topic?
Letter of St Irenaeus, Against Heresies, Chapter 3 (180 AD)
[we do this, I say,] by indicating that tradition derived from the apostles, of the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul; as also [by pointing out] the faith preached to men, which comes down to our time by means of the successions of the bishops. For it is a matter of necessity that every Church should agree with this Church on account of its preeminent authority
...The blessed apostles, then, having founded and built up the Church, committed into the hands of Linus the office of the episcopate. Of this Linus, Paul makes mention in the Epistles to Timothy. To him succeeded Anacletus; and after him, in the third place from the apostles, Clement was allotted the bishopric. This man, as he had seen the blessed apostles, and had been conversant with them, might be said to have the preaching of the apostles still echoing [in his ears], and their traditions before his eyes. Nor was he alone [in this], for there were many still remaining who had received instructions from the apostles.
Once again, this proves the authority of the Roman Catholic church, apostolic traditions and the succession of bishops.
In the passage above, we also know that Clement, who had seen the blessed apostles, and had been conversant with them, was ordained by Peter himself.
Clementâs Pontificate was c.88-89, he was whom St.Paul referred as a âco-laborer and fellow soldierâ in his greeting in Philippians 4:3.
Now knowing how close Pope Clement 1 was to the apostles, let's take a look at the Epistle to the Corinthians he wrote:
First Epistle of Clement to the Corinthians 44:1-3 (95 AD)
Our apostles also knew, through our Lord Jesus Christ, that there would be strife on account of the office of the episcopate. For this reason, therefore, inasmuch as they had obtained a perfect fore-knowledge of this, they appointed those [ministers] already mentioned, and afterwards gave instructions, that when these should fall asleep, other approved men should succeed them in their ministry.
The letter is a response to events in Corinth, where the congregation had deposed certain bishops. Pope Clement 1 called on the congregation to repent, to restore the bishops to their position, and to obey their superiors.
From the letter, it can been seen just as the apostlesâ authority was passed on their successors, Peterâs authority as the leader of the apostles was passed on to his successor to continue their ministry.
Jesus wanted the church to be in unity, as in his prayer to the Father,
John 17:11,20-22
And now I am no more in the world, but they are in the world, and I am coming to thee. Holy Father, keep them in thy name, which thou hast given me, that they may be one, even as we are one. ⊠"I do not pray for these only, but also for those who believe in me through their word, that they may all be one; even as thou, Father, art in me, and I in thee, that they also may be in us, so that the world may believe that thou hast sent me. The glory which thou hast given me I have given to them, that they may be one even as we are one,
That those who believe in Jesus will be in unity. It is unity not merely in the belief in Christ. It is the unity like how the Father and the Son are one.
Jesus wanted Christians to be "one flock, one shepherd"
John 10:16
And I have other sheep, that are not of this fold; I must bring them also, and they will heed my voice. So there shall be one flock, one shepherd.
Jesus wanted Christians to be under the same "flock", with the same "shepherd." This unity can only be found through the one Church that Jesus founded: the Catholic Church.
And through this Church, that Jesus wanted us to find companions,
Ephesians 2:19-21
So then you are no longer strangers and sojourners, but you are fellow citizens with the saints and members of the household of God, built upon the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure is joined together and grows into a holy temple in the Lord;
St Paul has also warned against schisms. He said,
1 Cor 1:10,13
I appeal to you, brethren, by the name of our Lord Jesus Christ, that all of you agree and that there be no dissensions among you, but that you be united in the same mind and the same judgment. ⊠Is Christ divided? Was Paul crucified for you? Or were you baptized in the name of Paul?
No one should break away from the Catholic church on the basis of their own beliefs that differ from the Catholic Church. St Paul appealed to us, Christians, to be united in the same thinking.
While there are times that the Church members did not uphold exemplary behaviour, including some popes, these actions by no means undermine the authority of the Catholic Church to teach infallibly. In fact, the apostles and Peter themselves are not perfect in their lives. The Catholic Church has been granted the gift of the Holy Spirit to never fall away from the truth. Whenever the pope speaks ex cathedra, or when a council is declared ecumenical, doctrines declared are safe to be considered infallible. The Catholic Church is the church that Jesus founded before He left, with the pope being the head of the Church.
The Catholic Church has a long history of intellectual pursuits, which are concluded from the councils. It is through thousands of years of discussions that the Catholic Church has the current set of doctrines. Many of them can be explained, while some are arguable. But remember that, they are the ones with the best knowledge of the Church, of the Bible, of how one should interpret passages. Personally, I have found many instances where the Church's knowledge of the Bible passages in Greek helps me get the correct understanding. In a way, as I am sharing my knowledge about Catholic faith, I am standing on shoulders of giants.
Some of you might wonder, aren't there too many doctrines to follow? Should we just stick to the Bible only? I would compare the Catholic church to the body of scientists. Many laws of Physics took years, even centuries, to be proven correct, and as we learn them in school, we are ignorant of how much sweat has gone into proving them. And that is how one should learn science! At times, people with curious mind would want to find out the proof of some theorems. But we should never break away from the complex body of science and say, we should stick to our own observations! That is how the modern flat Earth theory is formed. Flat Earthers stick to their own theories and observations to argue against the common belief of the round Earth. Similarly, the Church has been built upon centuries of intellectual pursuit. I as a Catholic may not know all doctrines, and may fully understand even fewer. But that is how I will commit as a Christian! I believe that the Catholic Church teaches correct doctrines. I at times may question the doctrines, and take time to find the answer. But I will never break away from the true church that Jesus has founded.